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Thermal Desorption Spectroscopy (TDS) and its Application for Research of Surface Processes
Potoček, Michal ; Čech, Vladimír (referee) ; Pavlík, Jaroslav (referee) ; Dub, Petr (advisor)
ermal desorption spectroscopy (TDS) is a common method for surface analysis of adsorbed molecules. In chapter 1 the work deals with the theoretical background of this method and shows the principles of a desorption process influenced by subsurface diffusion. Chapter 2 first shows application of TDS for detection of surface molecules and determination of binding energy.Experiments were mainly focused on ditermination of surface adsorbents and impurities on Si wafers. The second part of chapter 2 describes desorption of atoms of a Ga layer on Si surface and their subsurface diffusion. A Ga diffusion process was also observed by with secondary ion mass spectrometry (SIMS) and numerically simulated.
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Characterization of 1-D Nanostructures by SPM Methods
Škoda, David ; Čech, Vladimír (referee) ; Pavlík, Jaroslav (referee) ; Dub, Petr (advisor)
The thesis is aimed at the characterization of carbon nanotubes and silver nanowires by Scanning Probe Microscopy, namely Scanning Tunneling Microscopy (STM), Atomic Force Microscopy (AFM), Conductive AFM (CAFM) and Scanning Near-Field Optical Microscopy (SNOM). Carbon nanotubes were analyzed by STM, AFM and CAFM microscopy. In a designed apparatus the silver nanowires were fabricated by template assisted deposition and were analyzed with respect to their geometry (AFM), local conductivity (CAFM) and optical properties (SNOM, microreflex spectroscopy). It was found that preferential type of carbon nanowires depends on the fabrication process. The measurements of local conductivity of the nanotubes revealed the similarity with the STM measurements. The AFM measurements of silver nanowires confirmed their growth inside the pores of polycarbonate template. Single nanowires exhibits the semiconducting behavior according to I--V measurement and localized plasmon resonances.
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Study of plasma in the mixtures with molecular gas at wide pressure range
Morávek, Matěj Jan ; Hrachová, Věra (advisor) ; Mazánková, Věra (referee) ; Pavlík, Jaroslav (referee)
Study of plasma in the mixtures with molecular gas at wide pressure range Matěj Jan Morávek Abstract: The positive column of DC glow discharge sustained in oxygen and oxygen-nitrogen mixtures has been studied in two discharge tubes of the same shape made from different materials (Silica and Pyrex glass) for total pressures 650 - 2000 Pa and discharge currents up to 40 mA. Various parameters of the discharge - axial electric field strength, concentration of electrons and emission spectra - were studied with emphasis placed on transition region between low- and high-gradient form of the positive column. We have focused on the qualitative and quantitative analysis of the differences in emission spectra for both particular forms and the transitional region between them. The impact of 1 % admixture of nitrogen was also studied.
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Plazmové opracování porézních povrchů
Vaidulych, Mykhailo ; Hanuš, Jan (advisor) ; Pavlík, Jaroslav (referee) ; Tichý, Milan (referee)
Title: Plasma treatment of porous structures Author: Mykhailo Vaidulych Department / Institute: Department of Macromolecular Physics Supervisor of the doctoral thesis: Prof. Assist. Jan Hanuš, Ph.D., Department of Macromolecular Physics Abstract: The thesis is focused on the implementation of low-temperature plasma for the modification of porous materials. Two main strategies are involved: functionalization through the deposition of functional nanocomposite coatings and low-pressure plasma etching. In the first case, a gas-phase step-by-step deposition process based on the combination of deposition of nanoparticles and thin films was developed to obtain super-wettable nanocomposite coatings on filtration membranes. It was shown that the deposition parameters of thin films and particles of plasma polymer can tune the wetting characteristic of the membranes whereas embedding copper nanoparticles endows them with antibacterial properties. As a result, highly efficient superhydrophobic/superoleophilic and smart superamphiphilic membranes were successfully fabricated for oil/water separation. Plasma processing in the atmosphere of argon, oxygen or nitrogen was utilized to modify hard metal/polymer nanocomposites (Ag/a-C:H) with potential to be used as functional coatings for bone implants. An anisotropic etching...
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Thin films of plasma polymers as stable supports for biomedical applications
Gordeev, Ivan ; Shukurov, Andrey (advisor) ; Novák, Rudolf (referee) ; Pavlík, Jaroslav (referee)
Title: Thin films of plasma polymers as stable supports for biomedical applications Author: Ivan Gordeev Institute: Charles University in Prague, Department of Macromolecular Physics Supervisor of the doctoral thesis: Doc. Ing. Andrey Shukurov, Ph.D, Charles University in Prague, Department of Macromolecular Physics. Abstract: Plasma polymers have been widely considered for use as bio-active coatings. In biomedicine, the surfaces that withstand accumulation of biofilms are of particular importance. This thesis is focused on development of new plasma-based methods for deposition of bio-resistant (non-fouling) plasma polymers. Poly(ethylene oxide) was the subject material. R.f. magnetron sputtering, plasma-assisted thermal vapour deposition and amplitude modulated atmospheric pressure surface dielectric barrier discharge were the methods adapted to fabricate thin films with tunable chemical composition, cross-link density and biological response. A new insight was gained into the processes of plasma polymerization as well as into composition/structure relationship and its effect on biological properties of resultant films. Keywords: plasma polymerization, PEO, 'non-fouling' properties, protein adsorption, cell adhesion
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Nano-structured multicomponent plasma polymers for controlled immobilization of biomolecules
Melnichuk, Iurii ; Shukurov, Andrey (advisor) ; Čech, Vladimír (referee) ; Pavlík, Jaroslav (referee)
Title: Nano-structured multicomponent plasma polymers for controlled immobilization of biomolecules Author: Iurii Melnichuk Department / Institute: Department of Macromolecular Physics/Charles University Supervisor of the doctoral thesis: Doc. Ing. Andrey Shukurov, Ph.D. Abstract: The aim of this thesis is to highlight the feasibility of tailored nano- structures in functionalizing surfaces for biointerfacial interactions. Development of new techniques for the production of nanoscaled biomaterials can be of use in a variety of medical and biological applications, e.g. biosensors, microarrays, drug sensors, implants, blood-contacting devices. This thesis first examines the early stages of nano-structured thin film growth fabricated by vapor phase deposition of poly(ethylene). We discuss island growth within a framework of rate equation theory, dynamic scaling theory and capture zone distribution. In a second stage, we test dielectric barrier discharge to activate PE nano-pattern for covalent immobilization of proteins. Finally, we assess cell behavior on surfaces in dependence on morphology and the presence of cell adhesive protein tropoelastin. We employ plasma polymerization to produce ultrathin hydrocarbon layer capable of protein anchoring. The thesis findings for the first time manifest the critical...
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